Toluene and ethanol effects on baboon match-to-sample performance: possible synergistic action

Four juvenile male baboons were trained to respond for banana pellet rewards on a match-to-sample discrimination task. Exposure of the animals to a range of concentrations of either toluene or ethanol vapor resulted in a slowing of response times and a reduction in the percent trials attempted for some concentrations of either vapor. When behaviorally ineffective (subthreshold) concentrations of each vapor were combined, effects upon response times and trials attempted were similar to the effects produced by the higher concentrations of the individual vapors. However, while high concentrations of ethanol vapor produced errors in half of the subjects, combinations of ethanol and toluene did not increase this effect. This information suggests an ethanol potentiation of toluene effects, rather than the reverse.